1

Let me start to say that I'm new to iOS/Xcode programming so I don't know even what to ask exactly. I'm trying to add a static library to an app and I'm ending up with a crash. The library package has a .h file and a .a file. I'm asking for some suggestions about how to proceed to figure out the problem. Here some facts :

  • Xcode 7.3 - El captain OS
  • the library is working. I have a demo app that is working with no crash using the same library I'm trying to use

  • I didn't find significative differences comparing the demo app to mine. Mine is created from scratch (single View - storyboard), the demo app uses xib files and I don't know how it was developed. Some file are identical (i.e. copied directly from the demo app)

  • the crash apparently happens inside the library, in one of the internal calls

  • the crash involve the NSMutableData class. This is error:

    +[NSMutableData dataFromHexString:]: unrecognized selector sent to class 0x1a085fdb0

    *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[NSMutableData dataFromHexString:]: unrecognized selector sent to class 0x1a085fdb0'

    • In the code of the apps (both of them the one that is working and the one that is not working) there is no direct referral to the class NSMutableData. The closest class defined in the app is the NSMutableArray and for what I can see it is defined and used in the same way in both apps.

This why I don't know how to proceed. It must be something in the app that prevent the library to work, because it is working with the original demo code, but I have no idea at this point what it can be. I tried to put some breakpoints trying to pinpoint the problem but the library is compiled without debug info, so only assembly code inside the library is shown by the debugger. I'm looking for any clue about how to proceed.

Thanks for any help Steve

rmaddy
  • 314,917
  • 42
  • 532
  • 579
thefwguy
  • 85
  • 1
  • 11
  • 1
    There is no such method as `dataFromHexString:` for `NSMutableData`. Perhaps some library added it as a category method. – rmaddy May 13 '16 at 22:18
  • Correct, I noticed that that method is not present but in the working app I didn't find any method added to that class. In my app I'm including the exact same files of the working app. Is it possible some app configuration (info.plist or other) can do the trick ? – thefwguy May 13 '16 at 22:29

1 Answers1

1

Found the problem. I was chasing ghosts, the configuration was missing two compile flag. The method dataFromHexString is declared inside the static library and of course there is no documentation about that. I had to add two flags to compile the code : -ObjC and -all_load My guessing (I don't know yet very well the environment) is that with those flag the code is able to recognize the new method.

thefwguy
  • 85
  • 1
  • 11